KR102605099B1 - Line filter and power supply comprising line filter - Google Patents

Abstract

A line filter and a power supply device including a line filter are disclosed. The line filter includes a high-frequency choke that removes high-frequency noise above a preset frequency and a CM (Common Mode) choke that removes noise in the entire frequency band. The high-frequency choke is formed as a closed circuit and has two windows by the middle leg. A core divided into a core, a first winding and a second winding wound on at least one outer leg of the core, and the CM choke includes a core, a third winding wound on one outer leg of the core, and a core around which the third winding is wound. It includes a fourth winding wound on the outer leg of the other side facing the outer leg of .

Description

Line filter and power supply including line filter {LINE FILTER AND POWER SUPPLY COMPRISING LINE FILTER}

The present invention relates to a line filter and a power supply device including a line filter, and more particularly, to a miniaturized line filter and a power supply device including a line filter.

With the advancement of broadcasting technology, the size of TV panels is increasing. Since panel size and power consumption are proportional, a high-output power supply is required to drive a large panel. However, at the same time, power supply devices are required to be smaller and slimmer in line with the slimmer TV sets. Among the various components of the power supply included in a TV set, the line filter circuit is bulky because it consists only of passive elements. Additionally, because the value of passive elements must increase as power consumption increases, the volume of the passive elements also increases in proportion to their value.

Meanwhile, multiple line filters may be used in one power supply device. Generally, a common mode (CM) choke is used to remove noise in the entire frequency band, focusing on the low frequency band, and a high frequency choke is used separately to effectively remove noise in the high frequency band.

For example, Figure 1 is a diagram explaining the configuration of an existing power supply device. Referring to Figure 1, the power supply includes one high frequency choke and two CM chokes. As described above, the high frequency choke removes power noise in the high frequency band, and the two CM chokes remove noise in the entire frequency band.

Figure 2 is a diagram showing a line filter. Referring to Figure 2(a), a high frequency choke is shown, and to Figure 2(b), a CM choke is shown. As shown in Figure 2(a), the size of the high-frequency choke is approximately 15 mm wide and 17.5 mm vertical. And, as shown in Figure 2(b), the size of the CM choke is approximately 31 mm wide and 27 mm tall. As such, the line filter has a problem in that it occupies a large area in the power supply device. Therefore, technology for miniaturizing line filters is required.

The purpose of the present invention is to provide a line filter capable of miniaturizing a CM choke and a high-frequency choke, and a power supply device including a line filter.

Additionally, an object of the present invention is to provide a line filter that can simplify the production process and a power supply device including the line filter.

In order to achieve the above object, the line filter according to an embodiment of the present invention includes a high-frequency choke that removes high-frequency noise above a preset frequency and a CM (Common Mode) choke that removes noise in the entire frequency band; The high-frequency choke includes a core formed as a closed circuit and divided into two windows by a middle leg, a first winding and a second winding wound on at least one outer leg of the core, and the CM choke includes the core, a third winding wound around an outer limb of one side of the core, and a fourth winding wound around an outer limb of the other side facing the outer limb of the core around which the third winding is wound.

And, the first winding and the second winding of the high-frequency choke are wound on the outer leg of the first window area of the two windows of the core, and the third winding and the fourth winding of the CM choke are wound on the outer leg of the first window area of the two windows of the core. It can be wrapped around the outer edge of the second window area among the windows.

In addition, the first winding is wound on the outer leg of one side adjacent to the middle foot of the first window area, and the second winding is wound on the outer foot of the other side facing the outer foot of one side around which the first winding is wound in the first window area. It can be coiled.

Additionally, the first winding and the second winding may be wound side by side around an outer leg on one side facing the middle leg of the first window area.

Meanwhile, the first winding and the third winding are wound side by side around the outer foot on one side facing the midfoot, and the second winding and the fourth winding are wound side by side around the outer foot on the other side facing the midfoot, and the second winding and the fourth winding are wound side by side around the outer foot on the other side facing the midfoot. The winding may be arranged to face the first winding, and the fourth winding may be arranged to face the third winding.

Additionally, the two windows of the core may have different areas.

Additionally, the first winding and the second winding may have opposite winding directions, and the third winding and the fourth winding may have opposite winding directions.

Additionally, the first winding and the second winding may have the same number of windings, and the third winding and the fourth winding may have the same number of windings.

Also, the number of windings of the first winding may be less than the number of windings of the third winding.

In order to achieve the above object, a power supply device according to an embodiment of the present invention includes a power supply unit that receives power from the outside and a line filter that removes noise included in the input power, and the line filter is a It includes a high-frequency choke that removes high-frequency noise above a set frequency and a CM (Common Mode) choke that removes noise in the entire frequency band, and the high-frequency choke is formed as a closed circuit and divided into two windows by a middle leg. It includes a core, a first winding and a second winding wound around at least one outer leg of the core, and the CM choke includes the core, a third winding wound around an outer leg on one side of the core, and the third winding. and a fourth winding wound on the outer leg of the other side facing the outer leg of the wound core.

As described above, according to various embodiments of the present invention, a line filter and a power supply device including the line filter can be miniaturized by manufacturing a CM choke and a high frequency choke into one.

Additionally, the line filter and the power supply including the line filter can be manufactured as one, thereby simplifying the production process and reducing production costs.

1 is a diagram explaining the configuration of an existing power supply device.
Figure 2 is a diagram showing an existing line filter.
Figure 3 is a diagram showing a line filter according to the first embodiment of the present invention.
Figure 4 is a diagram showing a line filter according to a second embodiment of the present invention.
Figure 5 is a diagram showing a line filter according to a third embodiment of the present invention.
Figure 6 is a diagram illustrating a power supply device according to an embodiment of the present invention.
Figure 7 is a diagram showing another power supply device according to another embodiment of the present invention.
Figure 8 is a diagram showing the results of testing with and without a midfoot.

Hereinafter, various embodiments will be described in more detail with reference to the attached drawings. The embodiments described herein may be modified in various ways. Specific embodiments may be depicted in the drawings and described in detail in the detailed description. However, the specific embodiments disclosed in the attached drawings are only intended to facilitate understanding of the various embodiments. Accordingly, the technical idea is not limited to the specific embodiments disclosed in the attached drawings, and should be understood to include all equivalents or substitutes included in the spirit and technical scope of the invention.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but these components are not limited by the above-mentioned terms. The above-mentioned terms are used only for the purpose of distinguishing one component from another.

In this specification, terms such as “comprise” or “have” are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof. When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

In addition, when describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof is abbreviated or omitted.

Figure 3 is a diagram showing a line filter according to the first embodiment of the present invention.

The line filter 100 according to an embodiment of the present invention includes a high-frequency choke and a common mode (CM) choke. The high-frequency choke is a part that removes high-frequency noise included in the circuit line, and the CM choke is a part that removes noise in the entire frequency band.

Typically, most of the noise contained in circuit lines can range from hundreds of KHz to tens of MHz. Therefore, the CM choke can remove noise in the entire frequency band, focusing on noise in the low-frequency region. However, even if there are not many noise components in the high-frequency region, it has a significant impact on electronic devices, so it is necessary to reliably remove the noise component in the high-frequency region. Therefore, as described above, a high-frequency removal line filter capable of removing high-frequency noise is separately included.

However, the line filter 100 according to an embodiment of the present invention includes both a high frequency choke and a CM choke. That is, the line filter 100 according to an embodiment of the present invention may be implemented with a filter for removing noise in a high frequency region and a filter for removing noise in the entire frequency band. The line filter 100 may be implemented with some passive elements for impedance matching, including a high-frequency choke and a CM choke. Therefore, in this specification, the part including the high-frequency choke and the CM choke will be referred to as a line filter.

The line filter 100 includes a core 10 including a middle leg, a first winding 21 and a second winding 22 implementing a high frequency choke, a third winding 31 implementing a CM choke, and a third winding 31 implementing a CM choke. Contains 4 windings (32). The core is divided into regions by metapodia and may contain two windows. The sizes of the two windows may be the same, but may also be different.

As an example, a relatively small window area may be implemented with a high frequency choke, and a relatively large window area may be implemented with a CM choke. That is, the first winding 21 and the second winding 22 are wound around the outer leg of the relatively small window area of the core 10, respectively, and can be implemented as a high-frequency choke. In addition, the third winding 31 and the fourth winding 32 are wound around the outer edge of the relatively large window area of the core 10 and can be implemented as a CM choke.

A line filter is a filter that removes noise commonly present in circuit lines. Therefore, the first winding 21 and the second winding 22 must be wound in opposite directions. Also, the third winding 31 and the fourth winding 32 must be wound in opposite directions. The first winding 21 and the third winding 31 are input lines, and the second winding 22 and the third winding 32 are output lines. That is, the current input to the first winding 21 passes through several elements and is output to the second winding 22, and the current input to the third winding 31 passes through several elements and is output to the fourth winding 32. do.

A counterclockwise magnetic field is formed in the core 10 by current input from the upper lines of the first winding 21 and the third winding 31. The input current flows from the upper line to the lower line of the second winding 22 and the fourth winding 32 through various elements of the circuit. The magnetic field of the core is also formed in a counterclockwise direction by the current flowing in the third winding 22 and the fourth winding 32, and therefore, the magnetic field of the core becomes stronger. The stronger magnetic field cancels out and does not affect the differential current, and acts as a resistance to common noise, so common noise can be eliminated. The specific noise removal process will be described later.

On the other hand, if the inductance is low or the number of turns of the winding is small, the resonance point rises. That is, because the first winding 21 and the second winding 22 have a relatively small number of turns, the parasitic capacitance is low and a large impedance can be formed at a relatively high frequency. Accordingly, the first winding 21 and the second winding 22 can remove noise in the high frequency band. Since the third winding 31 and the fourth winding 32 have a relatively large number of turns, the parasitic capacitance is high and a large impedance can be formed at a relatively low frequency. Accordingly, the third winding 31 and the fourth winding 32 can remove noise across the entire frequency band, focusing on relatively low frequencies.

Accordingly, the number of turns of the first winding 21 and the second winding 22 included in the high frequency choke is less than the number of turns of the third winding 31 and the fourth winding 32 included in the CM choke. Since the first winding 21 and the second winding 22 form a high-frequency choke, the number of turns of the first winding 21 and the number of turns of the second winding 22 may be the same. Additionally, since the third winding 31 and the fourth winding 32 form a CM choke, the number of turns of the third winding 31 and the number of turns of the fourth winding 32 may be the same. The number of turns of each winding can be determined in various ways based on the frequency band to be removed, etc.

Referring to FIG. 3, the high-frequency choke is formed as a closed circuit, and includes a core 10 divided into two windows by a middle leg, a first winding 21 wound around at least one outer leg of the core 10, and It includes a second winding (22). And, the CM choke includes the same core 10, third winding 31, and fourth winding 32 as the core included in the high frequency choke. The core 10 is commonly used in high-frequency chokes and CM chokes. In one embodiment, the first winding 21 and the second winding 22 may each be wound on facing outer legs of a relatively small window area. As described above, the first winding 21 and the second winding 22 are wound in opposite directions. And, the first winding 21 and the second winding 22 can be wound the same number of times. The third winding 31 and the fourth winding 32 may each be wound on facing outer legs of a relatively large window area. The third winding 31 and the fourth winding 32 are wound in opposite directions. And, the third winding 31 and the fourth winding 32 can be wound the same number of times. Meanwhile, the third winding 31 is wound more times than the first winding 21, and the fourth winding 32 is wound more times than the second winding 22. Additionally, the third winding 31 and the first winding 21 are wound in the same direction, and the fourth winding 32 and the second winding 22 are wound in the same direction.

By implementing one line filter 100 including a high frequency choke and a CM choke using one core, the volume and area of the line filter can be reduced. Accordingly, the miniaturized line filter 100 can miniaturize and slimmer the circuit board and contribute to miniaturization and slimmerization of electronic devices. Additionally, the miniaturized line filter 100 can simplify the production process of the line filter and lower the production cost.

Meanwhile, the windings may be placed in various positions.

Figure 4 is a diagram showing a line filter according to a second embodiment of the present invention.

Referring to FIG. 4, a line filter 100a whose winding position has been changed is shown. As described above, the line filter 100a includes a high frequency choke and a CM choke. The CM choke includes a third winding 31 and a fourth winding 32 each wound on opposing outer limbs of one core. The high frequency choke includes a first winding (21) and a second winding (22). The first winding 21 and the second winding 22 may be arranged side by side. That is, the first winding 21 and the second winding 22 may be arranged on the outer leg facing the middle leg. As described above, the first winding 21 and the second winding 22 are wound in opposite directions, and the number of turns may be the same.

Figure 5 is a diagram showing a line filter according to a third embodiment of the present invention.

Referring to FIG. 5, a line filter 100b whose winding position has been changed is shown. 3 and 4 illustrate a line filter in which the two windows in the core have different sizes, and the high-frequency choke and the CM choke are distinctly formed in each window area. However, the size of the two windows within the core may be the same. In addition, the first winding 21 and the third winding 31 may be disposed on the same outer leg, and the second winding 22 and the fourth winding 32 may be disposed on the same outer leg centered on the middle leg. As described above, the first winding 21 and the second winding 22 are included in the high frequency choke, and the third winding 32 and the fourth winding 33 are included in the CM choke.

According to Figure 5, the line filter 100b includes a high frequency choke and a CM choke. The high frequency choke includes a core 10, a first winding 21 and a second winding 22, and the CM choke includes the same core 10, a third winding 31 and a fourth winding 32. . The first winding 21 and the third winding 31 can be wound side by side around the outer leg on one side facing the middle leg. In addition, the second winding 22 and the fourth winding 32 can be wound side by side on the outer arm on the other side of the outer arm around which the first winding 21 and the third winding 31 are wound. That is, centered on the middle leg, the first winding 21 and the third winding 31 can be wound around the same outer leg on one side, and the second winding 22 and the fourth winding 32 can be wound around the same outer leg on the other side. The second winding 22 may be arranged to face the first winding 21, and the fourth winding 32 may be arranged to face the third winding 31. The first winding 21 may be wound in the opposite direction to the second winding 22 and may be wound in the same direction as the third winding 31. The fourth winding 32 may be wound in the opposite direction to the third winding 31 and may be wound in the same direction as the second winding 22. The first winding 21 may be wound the same number of times as the second winding 22, and may be wound less times than the third winding 31. The fourth winding 32 is wound the same number of times as the third winding 31, and may be wound a greater number of times than the second winding 22. The number of windings can be determined in various ways based on inductance, frequency band to be removed, etc.

Figure 6 is a diagram illustrating a power supply device according to an embodiment of the present invention.

Referring to FIG. 6, an embodiment of a power supply device 1000a including a line filter 100 is shown. The power supply device 1000a includes a line filter 100 and may include an X capacitor (X-cap) and a Y capacitor (Y-cap) around the line filter 100. The X capacitor is a capacitor connected to both ends of the AC line, and the Y capacitor is a capacitor connected between the AC line and ground. The X capacitor can play a role in reducing low-frequency noise, and the Y capacitor can play a role in reducing high-frequency noise.

The power supply device 100 can receive AC input and transmit it to the equipment under test (EUT) through the line filter 100 and various capacitors. The EUT may be a device for testing by supplying power using the power supply device 100, or may be a device for testing the power supply device 100. In the case of general electronic devices, the main body of the electronic device or a regulator to supply power may be connected instead of the EUT.

As an example, the first and second windings of the line filter 100 may be connected to the AC line, and the third and fourth windings may be connected to the EUT. That is, the high-frequency choke part can be connected to the AC terminal, and the CM choke part can be connected to the EUT terminal.

To briefly explain the operation of the line filter, current within a certain period of time can be input from the AC power source, transferred to the first winding, third winding, and EUT, and output to the fourth winding and second winding. That is, in the case of a normal current, the direction is opposite when flowing through the first winding and when flowing through the second winding. Since this normal current is in differential mode, it may not be affected by the line filter. However, since power noise occurs simultaneously in the first and second windings, it may be in common mode. As described above, the magnetic field generated in the core of the line filter disrupts the flow of common mode power noise, so the line filter can remove power noise.

Figure 7 is a diagram showing another power supply device according to another embodiment of the present invention.

Referring to FIG. 7, an embodiment of a power supply device 1000b including a line filter 100 is shown. The power supply device 1000b includes a line filter 100 and may include an X capacitor (X-cap) and a Y capacitor (Y-cap) around the line filter 100.

As described above, the power supply device 100 can receive AC input and transmit it to an Equipment Under Test (EUT) through the line filter 100 and various capacitors. As an example, the third and fourth windings of the line filter 100 may be connected to the AC line, and the first and second windings may be connected to the EUT. That is, the CM choke part can be connected to the AC terminal, and the high frequency choke part can be connected to the EUT terminal.

Since only the connection terminal of the line filter of the power supply device 1000b of FIG. 7 has been changed from that of FIG. 6, further description will be omitted.

Figure 8 is a diagram showing the results of testing with and without a midfoot.

Referring to FIG. 8, test results of connecting the first to fourth windings to a core with a midfoot and a core without a midfoot are shown. A new core is a core described herein that includes a metapod, and an existing core is a core that does not include a typical metapod. L1 refers to the first winding, L2 refers to the second winding, L3 refers to the third winding, and L4 refers to the fourth winding. The first and second windings are included in the high frequency choke, and the third and fourth windings are included in the CM choke.

Referring to FIG. 8, when a core including a midfoot is used, the coupling degree between the first and second windings and the third winding and the fourth winding are high. That is, the coupling coefficient (K ₁₂ ) between the first winding and the second winding is close to 1. On the other hand, the coupling between the windings of the high-frequency choke and the CM choke is low. That is, the coupling coefficient (K ₁₃ ) of the first and third windings is close to 0. That is, the windings of the high-frequency choke and the windings of the CM choke operate without affecting each other. On the other hand, when using a core without a core, the degree of coupling between the windings of the high-frequency choke and the windings of the CM choke is also high. That is, the coupling coefficient (K ₁₃ ) of the first and third windings is close to 1. In other words, the efficiency is not good because the windings of the high-frequency choke and the windings of the CM choke affect each other. Accordingly, a line filter including a high-frequency choke and a CM choke formed integrally by winding a winding around a core including a middle leg can be miniaturized and exhibit superior performance.

100: Line filter 10: Core
21: first winding 22: second winding
31: third winding 32: fourth winding

Claims (10)

High-frequency choke that removes high-frequency noise above a preset frequency; and
Includes a CM (Common Mode) choke that removes noise in the entire frequency band,
The high frequency choke is,
A core formed as a closed circuit and divided into two windows by a middle leg, comprising a first winding and a second winding wound on at least one outer leg of the core,
The CM choke is,
It includes the core, a third winding wound around an outer limb of one side of the core, and a fourth winding wound around an outer limb of the other side facing the outer limb of the core around which the third winding is wound,
The first winding and the second winding have the same number of windings, the third winding and the fourth winding have the same number of windings,
A line filter, wherein the number of turns of the first winding is less than the number of turns of the third winding. According to paragraph 1,
The first winding and the second winding of the high frequency choke are wound around the outer leg of the first window area of the two windows of the core,
The third winding and the fourth winding of the CM choke are wound around an outer leg of a second window area of two windows of the core. According to paragraph 2,
The first winding is wound around the outer foot of one side adjacent to the middle foot of the first window area, and the second winding is wound around the outer foot of the other side facing the outer foot of one side around which the first winding is wound in the first window area. , line filter. According to paragraph 2,
The first winding and the second winding are wound side by side on an outer leg on one side facing the middle leg of the first window area. According to paragraph 1,
The first winding and the third winding are wound side by side around the outer foot on one side facing the midfoot, and the second winding and the fourth winding are wound side by side around the outer foot on the other side facing the midfoot,
The second winding is arranged to face the first winding, and the fourth winding is arranged to face the third winding. According to paragraph 1,
The two windows of the core have different areas, a line filter. According to paragraph 1,
The first winding and the second winding have opposite winding directions, and the third winding and the fourth winding have opposite winding directions. delete delete A power supply unit that receives power from the outside; and
It includes a line filter that removes noise contained in the input power,
The line filter is,
A high-frequency choke that removes high-frequency noise above a preset frequency, and
Includes a CM (Common Mode) choke that eliminates noise across the entire frequency band.
The high-frequency choke includes a core formed as a closed circuit and divided into two windows by a middle leg, a first winding and a second winding wound on at least one outer leg of the core,
The CM choke includes the core, a third winding wound around an outer limb of one side of the core, and a fourth winding wound around an outer limb of the other side facing the outer limb of the core around which the third winding is wound,
The first winding and the second winding have the same number of windings, the third winding and the fourth winding have the same number of windings,
The power supply device wherein the number of windings of the first winding is less than the number of windings of the third winding.

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